In recent years, a system in which a device that detects an object using data acquired from sensing devices such as a camera or a radar is mounted on a vehicle, and which causes a vehicle to automatically travel by the device, or supports a driver's driving operation is proposed. For example, in the device disclosed in Patent Literature 1, in a coordination mode in a case where there is no contradiction in a detection result of the vehicle by a plurality of sensors, the sensor performs a measurement of the vehicle. In the device disclosed in Patent Literature 1, in a case where contradiction in a detection result occurs, the sensors are in a master-slave mode, the sensor which has detected the vehicle becomes a master sensor and confirms the accuracy and the sensor which has not detected the vehicle becomes a slave sensor and performs a new search. In the device in Patent Literature 1, in a case where other than any one of the sensors is inoperable, only the operable sensors perform the measurement of the vehicle, in an independent mode.